Secretary of Defense Chuck Hagel and DoD comptroller Robert F. Hale confer as they prepare to testify before the Senate Armed Services Committee on the defense authorization request for FY 2015 in the Senate Hart Building, Washington, D.C. March 5, 2014.

WASHINGTON — Top Defense Department leaders appeared Wednesday before Congress to lay out the military’s plans to weather defense budget cuts, but the Russian incursion into Ukraine loomed over the proceedings.

The Pentagon on Tuesday formally announced a $496 billion 2015 base budget proposal that would cut the number of Army troops to as low as 440,000 in coming years, cut the number of Navy ships and cut well-regarded aircraft from the Air Force.

Department leaders recommended further savings by limiting troop pay increases, cutting the Basic Allowance for Housing, raising health care contributions by military retirees and families, and deeply cutting the subsidy to military commissaries.

Before Defense Secretary Chuck Hagel launched into an overview of the budget, he told members of the Senate Armed Services Committee that the U.S. military was stepping up joint training with troops in Poland, neighbor to both Ukraine and Russia, as well as increasing participation in NATO’s air policing mission in the Baltic region.

“It is a time for all of us to stand with the Ukrainian people in support of their territorial integrity and their sovereignty, and we are doing that,” Hagel said.

But Sen. John McCain, R-Ariz., pointed out that the budget proposal, if enacted by Congress would result in the smallest Army and Navy since before World War II, and a reduced Air Force. While the U.S. military shrinks, he said, Ukraine is in turmoil, negotiations with Iran over its nuclear program have collapsed, the Syrian conflict is expanding and China has announced major defense spending increases.

“I must say, Mr. Secretary, your timing is exquisite,” McCain told Hagel. “You’re coming over here … at a time when the world is probably more unsettled than it has been since the end of World War II.”

Republican senators and defense leaders sparred over who was really to blame for falling defense spending — the administration of President Barack Obama or Congress.

Sen. Kelly Ayotte, R-N.H., said Obama was prioritizing spending on civilian programs over national defense spending.

Hagel took exception, however, saying Congress has not provided the full defense spending amount requested in previous years.

“I think in the five budgets that this president has presented, they have been above … the ultimate number that we have received,” he said. “I can assure you that this President of the United States puts the defense of this country as his highest priority.”

Hagel and Chairman of the Joint Chiefs of Staff Martin Dempsey said while a recent bipartisan budget agreement provides enough funds to carry out the national defense strategy in 2015, that won’t be the case in 2016 if sequestration cuts begin again, as mandated by the Budget Control Act of 2011.

Resumption of $50 billion in yearly sequestration cuts would represent “unacceptable risk,” further slashing end strength, readiness and weapons purchases. Army end strength would have to fall to 420,000 troops, air wings and ships would be decommissioned, and an entire carrier group would be dropped, Hagel said.

As a result, Obama’s defense budget proposal plans for spending over a five-year period that is $115 billion higher than the Budget Control Act allows, which would require Congress to eliminate sequestration.

In addition, Obama proposed a spending package for 2015, known as the Opportunity, Growth and Security Initiative, that would add $26 billion to the defense budget to pay for additional modernization and maintenance, Hagel said.

Hagel and Dempsey also defended changes in pay and benefits, including shifting some housing costs to troops, more out-of-pocket Tricare expenses, slower pay growth and higher prices at commissaries.

“Taking care of our people means providing them with both fair compensation as well as the training and tools they need to succeed in battle any time anywhere and return home safely,” he said.

Dempsey added, “We have personnel costs that have grown at a disproportionate rate and we ought to be able to slow the rate in a way that makes the all-volunteer force sustainable over time.”

Both leaders also called on Congress to initiate a new round of base closures to rid the military of expensive and unneeded facilities.

“(W)e have infrastructure that we don’t need and — with your support — we ought to be able to reduce it,” Dempsey said.

Speaking the previous day, DOD comptroller Robert F. Hale went into greater depth on the need for a new round of closures.

“We’ve got at least 25 percent unneeded infrastructure in this department, and if we can’t get Congress to allow us to close it, then we’re simply going to waste the taxpayers’ money, frankly, and we won’t have that money to invest in other things like readiness and reducing the numbers of force cuts that are required.”

Sen. Kay Hagan, D-N.C., asked Hagel and Dempsey to keep in mind the strains and stresses that the personnel changes — particularly cuts and reorganization in Tricare — could put on military families.

“The department is laying out a number of proposals that would negatively affect military compensation,” Hagan said. “While I understand the significant fiscal challenges that the department faces, we just can’t see to balance the budgets on the backs of our servicemembers.”